React Native: Remove unused styles from external file

.react_native_strip_unused_styles.py

import re
import sys
from argparse import ArgumentParser

"""
A script to check a React Native view class and its stylesheet external file, removing unused style classes.
It search occurrences of given variable name (which must be the name of imported stylesheet class), comparing usages with
stylesheet class.
It eventually removes unused style classes from style file.
"""

def read_view_file(view_path, variable):
	"""Read the view class file checking usages of style defined as 'variable'
	
	Args:
	    view_path (TYPE): Path of file with view class
	    variable (TYPE): Name of imported variable of stylesheet class
	
	Returns:
	    TYPE: A list of found classes
	"""
	found = []

	with open(view_path, 'r') as j:
		line = j.readline()
		while line:
			m = re.findall(variable + '\.(\w+)', line)
			if m:
				for match in m:
					found.append(match)
			line = j.readline()

	print(found)
	print('\n\n')
	return found

def process_style_file(style_path, found):
	"""Process the stylesheet class removing style classes not found in 'found' list
	
	Args:
	    style_path (TYPE): Path of file with stylesheet class
	    found (TYPE): List of classes used by view class
	
	Returns:
	    TYPE: Updated content of stylesheet class without unused style classes
	"""
	style_content = ""
	with open(style_path, 'r') as j:
		line = j.readline()
		start = False
		include = True
		while line:
			if start:
				m = re.search('^    },', line)
				
				if m is not None:
					start = False
			else:
				m = re.search('^    (\w+): {', line)
				
				if m is not None:
					start = True
					match = m.group(1)
					if match not in found:
						include = False
					else:
						include = True
				elif not include:
					include = True
					
			if include:
				style_content = style_content + line
			line = j.readline()

	print(style_content)
	return style_content

def main(arguments):
	parser = ArgumentParser()
	parser.add_argument("-sf", "--stylefile", dest="stylefile",
	                    help="Style File path.", metavar="stylefile")
	parser.add_argument("-vf", "--viewfile", dest="viewfile",
	                    help="View File path.", metavar="viewfile")
	parser.add_argument("-v", "--variable", dest="variable",
	                    help="Style variable.", metavar="variable")

	args = parser.parse_args()

	style_path = args.stylefile
	if not style_path:
	    style_path = input('Enter style file path: ')
	view_path = args.viewfile
	if not view_path:
	    view_path = input('Enter view file path: ')
	variable = args.variable
	if not variable:
	    variable = input('Enter style variable: ')

	found = read_view_file(view_path, variable)
	style_content = process_style_file(style_path, found)

	overwrite = input('Do you want to overwrite style file? [y/n] ')
	if overwrite.lower() == 'yes' or overwrite.lower() == 'y':
		with open(style_path, 'w') as f:
			f.write(style_content)
		print("File written")

if __name__ == '__main__':
    sys.exit(main(sys.argv[1:]))

ExampleClassScreen.tsx

/*
 * Copyright (C) Christian Ascone - All Rights Reserved
 *
 * @file       LoginScreen.tsx
 * @author     Christian Ascone
 * @date       12/27/19 10:02 AM
 */

import React, {Component} from 'react';
import {ScrollView, TouchableOpacity, View, Text} from 'react-native';
import {i18n} from "@i18n/i18n";
import exampleClassScreenStyle from "@styles/ExampleClassScreenStyle";
import globalScreenStyle from "@styles/GlobalStyle";

export default class ExampleClassScreen extends Component<any, any> {
    static navigationOptions = {};

    constructor(props) {
        super(props);
    }

    render() {
        return (
            <View style={exampleClassScreenStyle.container}>
                <ScrollView
                    style={exampleClassScreenStyle.container}
                    contentContainerStyle={exampleClassScreenStyle.contentContainer}>
                    <View
                        style={[exampleClassScreenStyle.getStartedContainer, exampleClassScreenStyle.container, globalScreenStyle.globalMargins]}>
                        <View style={exampleClassScreenStyle.welcomeContainer}>
                            
                        </View>
                        <View style={exampleClassScreenStyle.inputContainer}>
                            
                        </View>
                        <View style={exampleClassScreenStyle.buttonContainer}>
                            
                        </View>
                        <TouchableOpacity style={exampleClassScreenStyle.buttonContainer}
                                          onPress={() => consle('Forgot')}>
                            <Text
                                style={exampleClassScreenStyle.forgotPassword}>Forgot</Text>
                        </TouchableOpacity>
                    </View>
                </ScrollView>
            </View>
        );
    }
}

ExampleClassScreenStyle.ts

/*
 * Copyright (C) Christian Ascone - All Rights Reserved
 *
 * @file       LoginScreenStyle.ts
 * @author     Christian Ascone
 * @date       9/17/19 3:27 PM
 */

import {Platform, StyleSheet} from "react-native";
import Colors from "../config/Colors";

const styles = StyleSheet.create({
    container: {
        flex: 1,
        backgroundColor: '#fff',
    },
    forgotPassword: {
        textAlign: 'right',
    },
    developmentModeText: {
        marginBottom: 20,
        color: 'rgba(0,0,0,0.4)',
        fontSize: 14,
        lineHeight: 19,
        textAlign: 'center',
    },
    contentContainer: {
        justifyContent: 'space-between',
        paddingTop: 30,
    },
    welcomeContainer: {
        flex: 1,
        marginTop: 10,
        marginBottom: 50,
    },
    inputContainer: {
        flex: 2,
        marginTop: 10,
        marginBottom: 20,
    },
    buttonContainer: {
        flex: 2,
        marginTop: 10,
        marginBottom: 20,
    },
    welcomeImage: {
        width: 150,
        height: 50,
        resizeMode: 'contain',
        marginTop: 3,
    },
    welcomeText: {
        flex: 1,
    },
    getStartedContainer: {
        height: '100%',
    },
    dashboardReservationsScreenFilename: {
        marginVertical: 7,
    },
    codeHighlightText: {
        color: 'rgba(96,100,109, 0.8)',
    },
    codeHighlightContainer: {
        backgroundColor: 'rgba(0,0,0,0.05)',
        borderRadius: 3,
        paddingHorizontal: 4,
    },
    getStartedText: {
        fontSize: 17,
        color: Colors.textColor,
        lineHeight: 24,
        textAlign: 'center',
    },
    tabBarInfoContainer: {
        position: 'absolute',
        bottom: 0,
        left: 0,
        right: 0,
        ...Platform.select({
            ios: {
                shadowColor: 'black',
                shadowOffset: {width: 0, height: -3},
                shadowOpacity: 0.1,
                shadowRadius: 3,
            },
            android: {
                elevation: 20,
            },
        }),
        alignItems: 'center',
        backgroundColor: '#fbfbfb',
        paddingVertical: 20,
    },
    tabBarInfoText: {
        fontSize: 17,
        color: Colors.textColor,
        textAlign: 'center',
    },
    navigationFilename: {
        marginTop: 5,
    },
    helpContainer: {
        marginTop: 15,
        alignItems: 'center',
    },
    helpLink: {
        paddingVertical: 15,
    },
    helpLinkText: {
        fontSize: 14,
        color: '#2e78b7',
    },
});

export default styles;